Scan Conversion . Jehee Lee Seoul National University. Attributes of Output Primitives. Handling attribute parameters Passing a list of attributes as a parameter of output primitive functions Eg) X-windows
Seoul National University
Projecting square cap
How can we generate a solid color/patterned polygon area?
A winding number is an attribute of a point with respect to a polygon that tells us how many times the polygon encloses (or wraps around) the point. It is an integer, greater than or equal to 0. Regions of winding number 0 (unenclosed) are obviously outside the polygon, and regions of winding number 1 (simply enclosed) are obviously inside the polygon.
(1) Find intersections (the extrema of spans)
(2) Sort intersections (increasing x order)
(3) Fill in between pair of intersections
: Start a point inside the figure, replace a specified interior color only.
Which is the better?
the sampling rate must be at least twice the frequency of the signal or aliasing occurs
1. Sample the scene at n times the display resolution.
2. The color of each pixel in the rendered image will be an average of several samples.